Communications system with speech-to-text conversion and associated methods

ABSTRACT

A communications system includes a first communications device cooperating with a second communications device. The first communications device multiplexes a digital speech message and a corresponding text message into a multiplexed signal, and wirelessly transmits the multiplexed signal. The second communications device wirelessly receives the multiplexed signal, de-multiplexes the multiplexed signal digital into the speech message and the corresponding text message, decodes the speech message for an audio output transducer, and operates a text processor on the corresponding text message for display. The corresponding text message is displayed in synchronization with the speech message output by the audio output transducer. A memory is coupled to the text processor for storing the text message, and the text processor is configured to display the stored text message.

FIELD OF THE INVENTION

The present invention relates to the field of wireless communications,and more particularly, to voice over wireless communications devices.

BACKGROUND OF THE INVENTION

Wireless communications devices transporting voice allows multipleparties to remain in contact with one another when deployed in thefield. These devices typically use low rate voice encoders (i.e.,vocoders) to robustly transmit digital speech to a receiver. On thereceive side, low rate voice decoders are used to convert the digitalspeech back to analog speech.

In noisy environments, the receiving party may have a difficult timehearing the speech message from the transmitting party. This means thatthe receiving party would have to ask for the speech message to beresent. If the link between the transmitting and receiving party is lostand cannot be reconnected, then the receiving party simply misses out onthe speech message. In certain situations the loss of a speech messageproviding command and control information may be critical. Consequently,there is a need to improve the reliability of the voice link between thetransmitting party and the receiving party.

One approach to addressing this problem is disclosed in U.S. Patent No.2006/0217159 which provides a wireless communications device that may beselectively operated in one of a voice-to-text operating mode and anaudible operating mode. In the voice-to-text operating mode, aspeech-to-text converter is used for converting a received speechmessage to a corresponding text message which is then sent to a displayfor viewing by the receiving party. Operation in the voice-to-textoperating mode may be based on a comparison of a measured ambient noiselevel and a predetermined threshold. Alternatively, a control signal forselecting the voice-to-text operating mode may be received over an airinterface. A disadvantage of this approach is that selection of thevoice-to-text operating mode may occur after the receiving party hasalready missed hearing a received speech message. A secondarydisadvantage is that most users have a need to hear the audio in orderto recognize the speaker on the other end.

SUMMARY OF THE INVENTION

In view of the foregoing background, it is therefore an object of thepresent invention to improve the reliability of a voice link in wirelesscommunications devices.

This and other objects, features, and advantages in accordance with thepresent invention are provided by a communications system comprising afirst communications device and a second communications devicecooperating therewith.

The first communications device comprises an audio input transducer, anda voice encoder coupled to the audio input transducer and configured toencode a speech message. A speech-to-text converter is coupled to theaudio input transducer and configured to convert the speech message intoa corresponding text message. A multiplexer is coupled to the voiceencoder and to the speech-to-text converter, and a wireless transmitteris coupled to the multiplexer. The multiplexer is operable to multiplexthe speech message and the text message into a multiplexed signal, andthe wireless transmitter is operable to transmit the combined (i.e.,multiplexed) signal.

The second communications device comprises a wireless receiverconfigured to receive the multiplexed signal from the wirelesstransmitter, and a de-multiplexer is coupled to the wireless receiverand de-multiplexes the multiplexed signal into the speech message andthe text message. A voice decoder is coupled to the de-multiplexer. Anaudio output transducer is coupled to the voice decoder and configuredto output the speech message. A text processor is coupled to thede-multiplexer. A display is coupled to the text processor and isconfigured to display the corresponding text message in synchronizationwith the speech message. A memory is coupled to the text processor andis operative to store the corresponding text message, and the textprocessor is configured to display the stored text message. In addition,the received voice message can be stored in a memory and played alongwith the text message.

The reliability of a voice link in the above described communicationssystem is advantageously improved based on a simultaneous transmissionof the speech message and the corresponding text message, whereinreception of the text message is displayed for viewing. This isaccomplished without requiring user input. In addition, there isadvantageously a stored record of transmission of the speech message,and possibly the speech text, from the first communications device forlater recall.

In noisy environments, the user operating the second communicationsdevice is still able to understand the speech message via display of thecorresponding text message even if the speech message was not audible.The display thus serves as a backup to the voice link.

Another aspect is directed to a mobile wireless communications devicecomprising a transmitter section and a receiver section cooperatingtherewith. The transmitter and receiver sections advantageously supportspeech-to-text conversion as described above.

Yet another aspect of the invention is directed to a method foroperating a communications system comprising first and secondcommunications devices as described above. The first communicationsdevice is operated to perform at least the following: encoding an analogspeech message to a digital speech message, converting the analog speechmessage into a corresponding text message, multiplexing the digitalspeech message and the corresponding text message into a multiplexedsignal, and wirelessly transmitting the multiplexed signal.

The second communications device is operated to perform at least thefollowing: wirelessly receiving the multiplexed signal, de-multiplexingthe multiplexed signal into the digital speech message and thecorresponding text message, decoding the speech message for an audiooutput transducer, operating a text processor on the corresponding textmessage for display. The corresponding text message is displayed insynchronization with the speech message output by the audio outputtransducer. In addition, the corresponding text message is stored, andthe text processor can be operated to later display the storedcorresponding text message, and optionally, the speech message too.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a wireless communications system inaccordance with the present invention.

FIG. 2 is a block diagram of an alternate embodiment of a wirelesscommunications system in accordance with the present invention.

FIG. 3 is a top level block diagram of mobile wireless communicationsdevices communicating with one another in accordance with the presentinvention.

FIG. 4 is a block diagram illustrating a method for operating a wirelesscommunications system in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will now be described more fully hereinafter withreference to the accompanying drawings, in which preferred embodimentsof the invention are shown. This invention may, however, be embodied inmany different forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art. Likenumbers refer to like elements throughout and prime notations refer toan alternate embodiment.

Referring now to FIG. 1, a wireless communications system 10 includes afirst communications device 20 and a second communications device 40cooperating therewith. Even though only first and second communicationsdevices 20, 40 are illustrated, the wireless communications system 10supports more than two communications devices, as readily appreciated bythose skilled in the art.

The communications devices 20, 40 are configured to support both voiceand data. Alternatively, the communications devices 20, 40 areconfigured to support voice-only.

The communications devices 20, 40 are intended to be deployed out in thefield so that communications is maintained between different users,particularly in noisy environments. As will be explained in greaterdetail below, a speech message and a corresponding text messagesynchronized with the speech message are exchanged between thecommunications devices 20, 40 so that if the speech message is notaudible by the receiving party, then the text message can be read, orboth can be heard (speech) and read (text) simultaneously.

The first communications device 20 includes an audio input transducer22, which may be a microphone, for example. A voice encoder 24 iscoupled to the audio input transducer, and is configured to encode aspeech message received by the audio input transducer 22. The voiceencoder 24 may operate at 600 bits/second, 1200 bits/second or 2400bits/second, for example. However, the voice encoder 24 is not limitedto these bit rates.

A speech-to-text converter 26 is coupled to the audio input transducer22. The speech-to-text converter 26 is configured to convert the speechmessage into a corresponding text message. The speech-to-text converter26 operates at a lower rate than the voice encoder 24. Thespeech-to-text converter 26 may operate at 50 bits/second or 75bits/second, for example. However, the speech-to-text converter 26 isnot limited to these bit rates.

A multiplexer 28 is coupled to the voice encoder 24 and to thespeech-to-text converter 26 to generate a multiplexed signal. Themultiplexed signal includes the speech message digitized and thecorresponding text message. In one embodiment, the multiplexer 28 isconfigured to substitute data bits from the speech-to-text converter 26within a bit stream from the voice encoder 24. However, this may degradeperformance of the voice encoder 24 since digital speech message bitsare being thrown away to accommodate the text message.

In another embodiment, the multiplexer 28 is configured to append databits from the speech-to-text converter 26 to the bit stream from thevoice encoder 24. As readily appreciated by those skilled in the art,the multiplexing may take place before the transport (i.e., physical)layer. Optionally, the multiplexing may take place in the transportlayer. When the multiplexing is performed at the transport layer,forward error correction (FEC) is being used. For example, the digitalspeech message may be at a rate of 2400 bps utilizing a rate 1/2 code inthe physical layer (physical layer runs at 4800 bps). The rate 1/2 codeis punctured to 2/3 so that 1200 bits are available to use for textmessage and text FEC. In this embodiment, puncturing does not throw awaythe original digital speech message bits. Instead, puncturing weakensthe FEC used to protect the digital speech message.

In another embodiment, when forward error correction (FEC) is used forthe physical layer waveform transporting digital voice, the FEC can bepunctured so that digital voice and speech can be sent withoutincreasing the data rate of physical layer waveform. In anotherembodiment, a weak FEC code or uncoded digital voice stream ismultiplexed with a strongly FEC coded text message. In anotherembodiment, the multiplexing can take place in the physical layerwaveform to allow more efficient use of a different FEC for speech andtext, etc.

A wireless transmitter 30 is coupled to the multiplexer 28. The wirelesstransmitter 30 transmits a multiplexed signal from the multiplexer 28over the airwaves via an antenna 32 coupled thereto.

The second communications device 40 includes an antenna 42 coupled to awireless receiver 44 to receive the multiplexed signal transmitted bythe first communications device 20. A de-multiplexer 46 is coupled tothe wireless receiver 44.

A voice decoder 48 is coupled to the de-multiplexer 46. An audio outputtransducer 50, such as a speaker, is coupled to the voice decoder 48. Atext processor 52 is coupled to the de-multiplexer 46. A display 54 iscoupled to the text processor 52 and is configured to display thecorresponding text message in synchronization with the speech message.

The communications system 10 advantageously allows a user operating thesecond communications device 40 to display the corresponding textmessage in synchronization with the speech message without requiringuser input. In noisy environments, the user operating the secondcommunications device 40 is still able to understand the speech messagevia the corresponding text message viewed on the display 54 even if thespeech message was not audible. The display 54 thus serves as a backupto the voice link.

In addition, a memory 47 is coupled to the text processor 52 for storingthe corresponding text message. This advantageously provides a storedrecord of transmission from the first communications device 20. Inaddition, the text processor 52 may be configured so that the user cancause the display 54 to display the saved corresponding text message.This advantageously allows the text message to be later recalled by theuser. Depending on the size of the display, the text message may bescrolled, as readily understood by those skilled in the art. Inaddition, each text message that is recalled has a time and date stampassociated with it, as well as identity of the sender. Optionally, thespeech message can also be stored and played back simultaneously withthe speech text.

Referring now to FIG. 2, an alternate embodiment of the wirelesscommunications system 10′ will be discussed. The first communicationsdevice 20′ may further comprise a language converter 27′ coupled betweenthe speech-to-text converter 26′ and the multiplexer 28′. Alternatively,the second communications device 40′ may comprise a language converter53′ coupled between the text processor 52′ and the display 54′.

Since the wireless communications devices 20′, 40′ may operate in amulti-language environment, the use of a language converter 27′, 53′advantageously allows a user to at least be able to read a received textmessage in their native language while the corresponding speech messageis audible in the sender's spoken language. This helps to improvecommunications among users from different nationalities. For example,the user operating the first communications device 20′ is English,whereas the user operating the second communications device 40′ isFrench. The language converter 27′, 53′ translates the text message fromEnglish to French. The language conversion may take place on thetransmit side or the receive side.

The respective users of the wireless communications devices 20′, 40′have the option of activating their respective language converter 27′ or53′. Each language converter 27′, 53′ may be configured to support oneor more different languages which allow the user to select the desiredlanguage for viewing the text message. Optionally, the text message canbe viewed in multiple languages simultaneously.

Optionally, the first communications device 20′ selects which languageto transmit. This determination may be made based on the languageproducing the smallest text message, for example. The correspondingtranslation is then made performed by the second communications device40′.

In the first communications device 20′, a noise pre-processor 23′ ispositioned between the audio input transducer 22′ and the speech-to-textconverter 26′. The noise pre-processor 23′ is configured to removebackground noise picked up by the audio input transducer 22′.

To further increase the robustness of the text message output by thereceiving radio 54′, error correction/detection may be used. Forexample, an error circuit 29′ is coupled between the speech-to-textconverter 26′ and the multiplexer 28′. In the second communicationsdevice 40′, an error circuit may also be included as part of the textprocessor 52′. The two error circuits cooperate with one another. Theerror circuits may operate based on forward error correction (FEC) andcyclic redundancy correction (CRC), for example.

Another aspect is directed to wireless communications devices 100 a, 100b that respectively include a transmitter section 102 a, 102 b and areceiver section 104 a, 104 b cooperating therewith, as illustrated inFIG. 3. A housing 106 a, 106 b carries the transmitter and receiversections 102 a, 104 a and 102 b, 104 b.

The transmitter and receiver sections 102 a, 104 a and 102 b, 104 bwithin each mobile wireless communications device 100 a, 100 badvantageously supports speech-to-text conversion as described above.The mobile wireless communications devices 100 a, 100 b communicate withone another to exchange speech messages and their corresponding textmessages as described above.

More particularly, each transmitter section 102 a,102 b includes thecomponents as illustrated in the first communications device 20, andtransmits a multiplexed signal that includes both a speech message and acorresponding text message. Similarly, each receive section 104 a, 104 bincludes the components as illustrated in the second communicationsdevice 40, and receives a multiplexed signal transmitted by a differentcommunications device. The received multiplexed signal is then separatedinto the speech signal for the audio output transducer, and into thetext message for display. The corresponding text message may be storedin a memory, and a text processor is configured to later display thestored text message.

A flowchart 150 illustrating a method for operating a communicationssystem 10 comprising a first communications device 20 and a secondcommunications device 40 cooperating therewith will now be described.From the Start (Block 152), the method comprises operating the firstcommunications device 20 to perform the following: encoding an analogspeech message to a digital speech message at Block 154, converting theanalog speech message into a corresponding text message at Block 156,multiplexing the digital speech message and the corresponding textmessage into a multiplexed signal at Block 158, and wirelesslytransmitting the multiplexed signal at Block 160.

The second communications device 40 is operated to perform thefollowing: wirelessly receiving the multiplexed signal at Block 162,de-multiplexing the multiplexed signal into the digital speech messageand the corresponding text message at Block 164, decoding the speechmessage for an audio output transducer at Block 166, and operating atext processor on the corresponding text message for display at Block168. The corresponding text message is displayed in synchronization withthe speech message output by the audio output transducer. Thecorresponding text message is also stored at Block 170, and the textprocessor is operated to display the stored corresponding text messageat Block 172. The method ends at Block 174.

Many modifications and other embodiments of the invention will come tothe mind of one skilled in the art having the benefit of the teachingspresented in the foregoing descriptions and the associated drawings.Therefore, it is understood that the invention is not to be limited tothe specific embodiments disclosed, and that modifications andembodiments are intended to be included within the scope of the appendedclaims.

1. A communications system comprising: a first communications device anda second communications device cooperating therewith, said firstcommunications device comprising an audio input transducer, a voiceencoder coupled to said audio input transducer and configured to encodea speech message, a speech-to-text converter coupled to said audio inputtransducer and configured to convert the speech message into acorresponding text message, a multiplexer coupled to said voice encoderand to said speech-to-text converter and operable to multiplex thespeech message and the corresponding text message into a multiplexedsignal, and a wireless transmitter coupled to said multiplexer andoperable to transmit the multiplexed signal; said second communicationsdevice comprising a wireless receiver configured to receive themultiplexed signal from said wireless transmitter, a de-multiplexercoupled to said wireless receiver and operable to de-multiplex themultiplexed signal into the speech message and the corresponding textmessage, a voice decoder coupled to said de-multiplexer, an audio outputtransducer coupled to said voice decoder and configured to output thespeech message, a text processor coupled to said de-multiplexer, adisplay coupled to said text processor and configured to display thecorresponding text message in synchronization with the speech message,and a memory coupled to said text processor for storing the textmessage, said text processor being configured to display the stored textmessage.
 2. The communications system according to claim 1 wherein saidfirst communications device further comprises a language convertercoupled between said speech-to-text converter and said multiplexer. 3.The communications system according to claim 1 wherein said secondcommunications device further comprises a language converter coupledbetween said text processor and said display.
 4. The communicationssystem according to claim 1 wherein said first communications devicecomprises a first error circuit coupled between said speech-to-textconverter and said multiplexer.
 5. The communications system accordingto claim 4 wherein said text processor comprises a second error circuitcooperating with said first error circuit.
 6. The communications systemaccording to claim 1 wherein said multiplexer is configured tosubstitute data bits from said speech-to-text converter within a bitstream from said voice encoder.
 7. The communications system accordingto claim 1 wherein said multiplexer is configured to append data bitsfrom said speech-to-text converter to a bit stream from said voiceencoder.
 8. The communications system according to claim 1 wherein eachof said first and second communications devices comprises a voice-onlycommunications device.
 9. A mobile wireless communications devicecomprising: a transmitter section and a receiver section cooperatingtherewith, said transmitter section comprising an audio inputtransducer, a voice encoder coupled to said audio input transducer, aspeech-to-text converter coupled to said audio input transducer, amultiplexer coupled to said voice encoder and to said speech-to-textconverter and configured to multiplex a digital speech message and acorresponding text message into a multiplexed signal, and a wirelesstransmitter coupled to said multiplexer and operable to transmit themultiplexed signal; and said receiver section comprising a wirelessreceiver configured to receive the multiplexed signal from said wirelesstransmitter, a de-multiplexer coupled to said wireless receiver andoperable to de-multiplex the multiplexed signal into the speech messageand the corresponding text message, a voice decoder coupled to saidde-multiplexer, an audio output transducer coupled to said voicedecoder, a text processor coupled to said de-multiplexer, a displaycoupled to said text processor and configured to display thecorresponding text message in synchronization with the speech message,and a memory coupled to said text processor for storing the textmessage, said text processor being configured to later display thestored text message.
 10. The mobile wireless communications deviceaccording to claim 9 further comprising a housing containing saidtransmitter section and said receiver section.
 11. The mobile wirelesscommunications system according to claim 9 wherein said transmittersection further comprises a language converter coupled between saidspeech-to-text converter and said multiplexer.
 12. The mobile wirelesscommunications system according to claim 9 wherein said receiver sectionfurther comprises a language converter coupled between said textprocessor and said display.
 13. The mobile wireless communicationssystem according to claim 9 wherein said multiplexer is configured tosubstitute data bits from said speech-to-text converter within a bitstream from said voice encoder.
 14. The mobile wireless communicationssystem according to claim 9 wherein said multiplexer is configured toappend data bits from said speech-to-text converter to a bit stream fromsaid voice encoder.
 15. A method for operating a communications systemcomprising a first communications device and a second communicationsdevice cooperating therewith, the method comprising: operating the firstcommunications device to perform at least encoding an analog speechmessage to a digital speech message, converting the analog speechmessage into a corresponding text message, multiplexing the digitalspeech message and the corresponding text message into a multiplexedsignal, and wirelessly transmitting the multiplexed signal; andoperating the second communications device to perform at leastwirelessly receiving the multiplexed signal, de-multiplexing themultiplexed signal into the digital speech message and the correspondingtext message, decoding the speech message for an audio outputtransducer, operating a text processor on the corresponding text messagefor display, with the corresponding text message being displayed insynchronization with the speech message output by an audio outputtransducer, storing the text message, and operating the text processorto display the stored corresponding text message.
 16. The methodaccording to claim 15 wherein operating the first communications devicefurther comprises converting the corresponding text message into adifferent language.
 17. The method according to claim 15 whereinoperating the second communications device further comprises convertingthe corresponding text message into a different language for display.18. The method according to claim 15 wherein multiplexing the digitalspeech message and the corresponding text message by the firstcommunications device comprises substituting data bits from thecorresponding text message within a bit stream of the digital speechmessage.
 19. The method according to claim 15 wherein multiplexing thedigital speech message and the corresponding text message by the firstcommunications device comprises appending data bits from thecorresponding text message to a bit stream of the digital speechmessage.
 20. The method according to claim 15 wherein each of said firstand second communications devices comprises a voice-only communicationsdevice.